The Question

(Submitted July 13, 2000)

Do the concepts of solitons and instantons help
or play a role in explaining dark matter or the missing
mass of the universe?

The Answer

Dark matter research requires the combined efforts of astrophysicists,
cosmologists and particle physicists. We at the "Ask an Astrophysicist" service can tell you a lot about the astrophysical aspects
of dark matter research; particle physics is somewhat outside our areas
of expertise, however.

We do belive that much of the dark matter is non-baryonic.

A part of this is likely to be massive neutrinos. Recent research on
neutrino oscillations (apparent mutation of neutrinos from one type to
another) strongly suggests they do have rest masses. They appear to
be insufficient to account for all the astrophysically inferred dark matter
mass in the Universe, though.

The rest are thought to be more exotic particles, with names like axions,
photinos, and so on. Our understanding is that there are plenty of
theoretical candidates for what the dark matter may consist of, but no
experimental evidence of a specific type of exotic particles. We do not
know if the concepts of solitons and instantons are relevant, or useful,
to particle physicists working on the dark matter: you may want to check
particle physics-oriented web sites, such as:

Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.